• Journal of the Institute of Electronics and Information Engineers
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• 제52권3호
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• pp.39-47
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• 2015

In this paper, we propose a new time synchronization algorithm using CoAP(constrained-application protocol) in sensor network environment, which handles a technique that synchronizes an explicit timestamp between sensor nodes not including an additional module for time-setting and sensor node gateway linked to internet time server. CoAP is a standard protocol for sensor data communication among sensor nodes and sensor node gateway to be built much less memory and power supply in constrained network surroundings including serious network jitter, packet losses, etc. We have supplied an exact time synchronization implementation among small and cheap IP-based sensor nodes or non-IP based sensor nodes and sensor node gateway in sensor network using CoAP message header's option extension. On behalf of conventional network time synchronization method, as our approach uses an exclusive protocol 'CoAP' in sensor network, it is not to become an additional burden for synchronization service to sensor nodes or sensor node gateway. This method has an average error about 2ms comparing to NTP service and offers a low-cost and robust network time synchronization algorithm.

• Journal of the Institute of Electronics and Information Engineers
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• 제50권9호
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• pp.144-155
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• 2013

This paper presents a low-cost remote power-quality-failure monitoring system (RPMS) using Android App and TI MCU (micro-controller unit), which is appliable to a micro-grid. The designed RPMS testbed consists of smart nodes, a server, and Android APPs. Especially, the C2000-series MCU-based RPMS smart node that is low-cost compared to existing monitoring systems has both a signal processing function for power signal processing and a data transmission function for power-quality monitoring data transmission. The signal processing function implements both a wavelet-based power failure detection algorithm including sag, swell, and interruption, and a FFT-based power failure detection algorithm including harmonics such that reliable and real-time power quality monitoring is guaranteed. The data transmission function implements a low-complexity RPMS transmission protocol and defines a simple data format (msg_Diag) for power monitoring message transmission. We may watch the monitoring data in real time both at a server and Android phone Apps connected to the WiFi network (or WAN). We use RS-232 (or Bluetooth) as the wired (or wireless) communication media between a server and nodes. We program the RPMS power-quality-failure monitoring algorithm using C language in the CCS (Code Composer Studio) 3.3 environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2001년도 춘계종합학술대회
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• pp.667-671
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• 2001

The Instant Messenger(IM) is the most popular personal communication tool today. IM is a tool that can substitute E-mail for a person, and can secure the user for a company. Further, it is claimed as it has a limitless potential. However, there has been several reports on security issues. It has known that the transmitting message is not secured for the attacks, and hacking tools has been developed. In addition, several reports has been made regards to the vulnerability. In other words, anyone can been through and manipulate the messages that are sent or received via IM. This is a barrier for the IM to be developed as a corporate's strategic tool, and furthermore, it will create serious personal privacy issue. IETF IMPP Working Group is preparing a standard mutual relationship between IM. However, it is complicated due to the American On-Lines's absence, whom has ensured the most number of IM users. There was a discussion only about the form of the transmitting data, but it is insufficient state to discuss the security service for general. In this paper, I design and implement the Secure Instant Messaging System, to solve the IM's vulnerability and the security issue presented above.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제9권6호
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• pp.1302-1308
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• 2005

Propose Cellular-IP/PRC network with united paging and Cellular IP special duality that use roof information administration cache to secure lake acceptance method in wireless Internet environment and QoS in lesser extent cell environment. When speech quality is secured considering increment of interference to receive in case of suppose that proposed acceptance method grooves base radio station capacity of transfer node is plenty, and moat of contiguity cell transfer node was accepted at groove base radio station with a blow, groove base radio station new trench lake acceptance method based on transmission of a message electric power estimate of transfer node be. Do it so that may apply composing PC(Paging Cache) and RC(Routing Cache) that was used to manage paging and router in radio Internet network in integral management and all nodes as one PRC(Paging Router Cache), and add hand off state machine in transfer node so that can manage hand off of transfer node and Roaming state efficiently, and studies so that achieve connection function at node. Analyze benevolent person who influence on telephone traffic in system environment and forecasts each link currency rank and imbalance degree, forecast most close and important lake interception probability and lake falling off probability, GoS(Grade of Service), efficiency of cell capacity in QoS because applies algorithm proposing based on algorithm use gun send-receive electric power that judge by looking downward link whether currency book was limited and accepts or intercept lake and handles and displays QoS performance improvement.

• Science of Emotion and Sensibility
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• 제9권2호
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• pp.93-100
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• 2006

This paper aims at the development and clinical evaluation of the wireless gyro-mouse system. The wireless gyro-mouse system is a computer interface with gyro-sensor and wireless communication, for the patients with upper-extremity disabled from the traffic accident or stroke to use the computer software i.e. internet browser. In the development, we focused on, firstly, to make the system wireless for the patients to manipulate the mouse easily even on the bed or wheelchair, secondly, to insert the gyro-sensor into a headband for easy don-and-doff and aesthetic appearance, thirdly, to devise a click switch in case of $C5{\sim}C6$ patients and a head nodding detection in case of C4 patients for sending click message to computer operating system. We performed evaluation experiment for patients with upper-extremities disabled from spinal cord injury. The results show that the displacement error of the cursor position against the target position during linear (vertical/horizontal) movement manipulation decreased with trial number. The click rate per minute also increased with trial number. This indicates the developed wireless gyro-mouse system would be more useful to the patients with repetitive use.

• Journal of Digital Convergence
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• 제14권11호
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• pp.241-247
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• 2016

As a domestic traffic control signal system, either the system with which a traffic signal turns into green at regular intervals or the system with which an amber or a red signal flickers on local roads without heavy traffic at midnight has been utilized. However, when the former system is used for roads with light traffic at midnight, delays and congestion can be incurred. Besides, in case of the latter signal system, the risk of vehicle crash is high. This study proposes a response type of flickering green signal system that rearranges signal system after analyzing beacon messages including sensor data. The proposed system, on a trunk road or a branch road at midnight, makes the signal keep flickering in green; When a vehicle enters the range of RSE, the transfer coverage, it transmits beacon messages regularly and Agent System analyzes the messages and alters the signal. It is a system by which vehicles move following the altered signal system, which will not only ensure smooth flow but also prevent vehicles from crashing on a road with light traffic. As a result of a simulation, traffic throughput and the average waiting time displayed 10 to 30 percent better improvement than existing signal systems, in terms of performance.

• Geophysics and Geophysical Exploration
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• 제3권2호
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• pp.53-60
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• 2000

The server/client systems using the web protocol and distribution computing environment by network was applied to the MT data processing based on the Java technology. Using this network based system, users can get consistent and stable results because the system has standard analysing methods and has been tested from many users through the internet. Users can check the MT data processing at any time and get results during exploration to reduce the exploration time and money. The pure/enterprised Java technology provides facilities to develop the network based MT data processing system. Web based socket communication and RMI technology are tested respectively to produce the effective and practical client application. Intrinsically, the interpretation of MT data performing the inversion and data process requires heavy computational ability. Therefore we adopt the MPI parallel processing technique to fit the desire of in situ users and expect the effectiveness for the control and upgrade of programing codes.

• Journal of architectural history
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• 제15권4호
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• pp.37-56
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• 2006

Introducing International Style, P. Johnson and H. R. Hitchcock gave three standards to be the Modern, volume and surface, regularity, and exclusion of applied decoration. In spite of the negation of stylistic, formal approach in the Modernist Manifestoes, one usually have understood Modernity in Architecture with its formal character, especially with no ornament and flat, abstract, white surface. Modernism as a new paradigm in architecture have emphasized that there is no representation of anything outside and only present architecture in itself. They said that Modernism only cared about the language of Architecture without figural reference. So apparently there is no way to prove to its Modernity with formal condition. Modernity is in Spirit and contents. But actually we understand well its existence by visual communication This study deals with this difficult situation how Modernity represents itself without visual media and asks the question how simultaneously it presents its thingness and materiality In order to analyse contradictory situation between representation and presentation in Modern Architecture we need to survey the historical process of changing position of ornaments and its meaning in time. With the crisis of representation the role of ornament have seriously changed and divided. It caused the two situation in pre-Modern Architecture. Firstly, Architecture tend to be a high art and formal expression became important much more. The Use of Ornament became a kind of fashion to show the power, class, money. Secondly, Ornament lost its cultural weight and the structure and material aspect became the central in architecture. Rational Structuralism would be the essential character in Modern Architecture. Here the theory of G. Semper and A. Loos on cladding(dressing) and Ornament can help its problems and limits. In the situation without conventional ornament Modernists need to present modernity with new media that only show the thing itself and by that it does not represent any thing else as like the value, idea outside buildings. They believed that only it concerned esthetics and morality in architecture. But in reality it referred to art and machines as like ships, aircraft, and cars. By excluding Ornament and showing the process of clearing, abstract, flat, white surface 'represent' Modernity by the indirect way referring the concept of transparency, reason, sanitation, tectonics, etc. An Ideology and myth intervened architectural discourse to make the doxa about the representation in Architecture. Surface must be a different kind of media and message that can communicate in different way with compared to conventional Ornament. Decorated Shed by R. Venturi and Post-Functionalism by P. Eisenman, that are the most famous post-modern discourse, shows well difficult and contradictory condition in contemporary architecture concerning representation and form, meaning and form.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.560-565
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• 2002

In this paper, we implemented the sign board system that displays user's image, user's sentence, the information from DARC an[1 information based position by GPS module for vehicle. The existing sign board is displaying only user's image and sentence. Or other existing sign board is displaying the information via CDMA network. However, our system is also able to display the user's message like other system and gain the information more cheap by DARC. This system consists of 6 parts. The DARC control part classes the DARC information - news, weather, stock and time. The GPS control part gains moment and item to display with calculating the information of global position, direction, speed and satellite. The LED control part has two buffers to store and handle the image. The buffers help the system display various effected images on LED board. An external memory card includes the location based data, the option file and the displayed data files. The data files are stored by FAT 16 with the folder structure on external memory card. The USB controls the communication with PC. PC programs can control and monitor this system. This system is using G72l voice file format, for casting the information. This system was established at the vehicle and we monitored this system. The system displayed the DARC data , user's data and the location based data on the LED board, successfully.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.685-688
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• 2016

SBAS(Satellite Based Augmentation System) broadcasts the correction message based on satellite communication to improve the positioning accuracy of GNSS user. For this reason, SBAS is actively being utilized on navigation part. To apply SBAS to navigation part, it should satisfy not only accuracy but also integrity, continuity, availability, coverage requirements and so on. Since SBAS reference station is the base infrastructure of SBAS, it is the main factor to determine the environment, position, and geometry of reference stations to achieve SBAS service performance. Therefore, a site environmental analysis should be performed prior to the selection of SBAS reference station. In this paper, it performs the environmental analysis of NDGPS(Nationwide Differential GPS) reference station sites on the premise that SBAS reference station will be co-operated in the same site of NDGPS operated by MOF(Ministry of Oceans and Fisheries). The environmental analysis is conducted as carrying out the visibility analysis of GPS satellite and interference analysis. This paper also presents the brief procedures and requirements for site survey of SBAS reference station.